The common causes of redness, swelling, hardness, itching and fever on the legs are folliculitis, allergic urticaria, papular urticaria, dengue, etc., and the treatment is mainly for the cause of the treatment, drug treatment, etc.. 1. severe folliculitis caused by redness, swelling, hardness, itchy and feverish symptoms on the legs, can apply medication, for bacterial infections caused by folliculitis can also apply antibiotics, such as penicillin, gentamicin and other medications, after the acute stage can also be used externally adapalene gel, neomycin ointment, etc., and should also avoid alcohol and spicy stimulating diet. 2. Allergic urticaria caused by redness, swelling, hardness, itching and fever on the legs, mainly to avoid contact with substances that can cause allergies, as well as the application of loratadine, glucocorticoids and other drugs for treatment. 3. For papular urticaria caused by local application of fluticasone propionate cream and other glucocorticoid creams, or 1% peppermint glycerite lotion to relieve the symptoms of itching, but also oral benadryl, loratadine and other antihistamines for treatment. 4. Dan toxicity caused by redness, swelling, hard lumps on the legs itching fever treatment is mainly the application of penicillin and other antibiotics or local application of 0.5% furacilin solution or 25% to 50% magnesium sulfate solution for wet compresses. When the symptoms of redness, swelling, hardness, itching and fever appear on the legs, you should go to the regular hospital, clear cause and follow the doctor’s instructions for treatment.